Traffic signs usually are attached to mounting posts which are rammed into the ground, into a street, or sidewalk. Frequently, such posts (in the following referred to as “sign posts”) are hit by vehicles, for example, during a parking maneuver of a vehicle in the vicinity of a sign post, or due to an accident or loss of control of a vehicle nearby a sign post. Due to the impact of the vehicle, the post is damaged and deformed wherein it remains broken and no longer allows for an unobstructed view of the traffic sign; due to a particularly strong impact, the post may virtually shatter.
The governing authority for traffic signs, for example, a municipal administration responsible for roads, therefore, has to spend substantial costs for monitoring, maintenance of the damaged sign posts, and the complete replacement of the posts which have been broken or have been bent beyond a certain range of tolerance.
According to several solutions from prior art, this problem is encountered by subdividing the sign posts nearby its basis into two portions, and to unite both portions by means of a coil spring which is arranged outside of the two portions. The coil spring functions as linking member between the two portions and allows for flexibility of the post which in case of an impact is tilted elastically, and then returns to its vertical position. Such solutions are, for example, known from US 2008/0067299 A1 or from U.S. Pat. No. 5,207,175.
A first disadvantage associated with these solutions lies therein that the external coil spring due to its technically inherent features is not able to sufficiently stabilize the sign post in normal circumstances. For example, a post having a height of 3 meters including the traffic sign which is attached to the upper end has a weight and torque exerted by wind being greater than may be compensated by the coil spring. Such a sign post in normal circumstances has little stability, sways continuously, and may be inclined by the pressure of wind substantially.
Moreover, in case the post is damaged, it is necessary to remove the entire post including its base, and a new post has to be erected by also renewing the basis. Such sign posts made from two portions and having a coil spring connection have to be completely assembled in the workshop, and therefore, on the road, it is not possible to only replace the upper portion and to leave the basis unaffected.
A second disadvantage, therefore, is associated with the costs and the complexity of the maintenance of the sign posts which are provided with an exterior coil spring. An additional fact which adds on the latter is that the external coil spring may be exposed to damage and may have an unaesthetic appearance.
From AU 43436 A, a post pedestal is known having a base plate at the upper side of which a reset ring is arranged. The reset ring engages a lower opening of a pipe being arranged perpendicular to the base plate at the upper end of which a sign post is attached. A U-shaped bolt is arranged within the reset ring and the upper side of the base plate which engages with an eyebolt wherein the eyebolt protrudes into the interior of the pipe. A coil spring is arranged at the eyebolt which is to exert a certain reset force such that the pipe returns to its upright position.
This solution is disadvantageous in that due to the arrangement of the U-shaped bolt and the eyebolt with respect to each other, the pipe may no longer be tilted in all directions. A tilting of the pipe obliquely to the U-shaped bolt may even lead to the U-shaped bolt or the eyebolt being deformed or even damaged.
From EP 0112804 A2, a traffic post is known which after having been tilted should erect itself again autonomously. In a first embodiment, an elastic rubber tube is arranged in the pipe interior in the area of the joint which exerts a certain reset force. In a second embodiment, a coil spring is arranged in the upper part of the pipe which is formed in two pieces which is coupled to a rope. The rope is guided in a guidance gap in a lower part of the pipe, is deflected there at a deflection disk, and is guided in a further guidance gap back to the upper part of the pipe. A similar traffic post is also known from AU 766749 B2.
From DE 86 07 898 U, a barrier device for parking lots is known. The barrier device has a pedestal with a post arranged thereon which is tiltable on the pedestal. In the interior of the post, a coil spring is arranged which is to exert a certain reset force when the post is tilted such that the post returns to its upright position again.